Frame of Reference as Subject in Subjective Idealism

[owl]

Cap 'n R,

Please address my "airtight logic" above.

If earth does not morph, it cannot change from spherical to very oblate. It must be one or the other, i.e., it can not be both. It's diameter can not be "different lengths."

Edited August 17, 2011 by owl

[Cap'n Refsmmat]

In any given reference frame, the Earth never changes shape. Two people in two different reference frames can concurrently view the Earth as being different shapes, but the Earth never changes shape in a single observer's frame.

 

This works if you consider a four-dimensional spacetime.

 

Length contraction in four-dimensional spacetime is not a "morphing" of shape or a result of any change in shape by the object whatsoever. It's a result of different portions of the object being visible to different reference frames; we see a three-dimensional "slice" of the 4D object.

[swansont]

We agree that objects don’t change shape and size (in the context of length contraction.) But there is a big difference between my claim that they just look different from different frames of reference and your claim that they are different, "have different lengths in different frames of reference."

 

Yes, those are different claims. One can reword the science claim to say that using identical protocols of measurement you will get these different answers. (that is, it is independent of any measurement errors)

 

Case in point, using absolutely airtight logic:

If earth does not morph, it cannot change from spherical to very oblate. It must be one or the other, i.e., it can not be both. It's diameter can not be "different lengths."

 

Not airtight. Far from it: it suffers from the fallacy of four terms

http://en.wikipedia.org/wiki/Ambiguous_middle_term

 

Your premises refer to observations in a single frame of reference. But the conclusion refers to a measurement comparison between two frames. At no point did you establish any relationship concerning the invariance of length between frames. Relativity says that it is not invariant. You cannot disprove that with measurements from a single frame.

 

You guys constantly avoid the thread title question.

“For” a muon, you say the atmosphere is way less than 200 miles thick. This is based on the following faulty logic:

We "know” the above because incoming muons “live” longer and travel further than “expected” based on observation of lab muons, so the distance traveled must be shorter than the established depth of atmosphere. Some logic!

 

Denigrating the logic because you disagree or don't understand it is hardly an argument. If you disagree you need something more than argument from incredulity.

[owl]

swansont:

Yes, those are different claims. One can reword the science claim to say that using identical protocols of measurement you will get these different answers. (that is, it is independent of any measurement errors)

 

You can “reword” it all you want and appeal to “protocols of measurement without error”, but since the earth doesn’t drastically change shape, it IS either very oblate or nearly spherical. In all honesty, it can not be both, in the “real world.”

 

Not airtight. Far from it: it suffers from the fallacy of four terms

http://en.wikipedia....ous_middle_term

 

I have taught university level “Logic and the Scientific Method” and you are way out of your element (field of expertise) here. I don’t intend to embarrass you personally, but you have grossly misapplied the “fallacy of four terms,” which I just reviewed from your link.

 

First I am not using a “categorical syllogism” as exemplified in your link. Rather I am using a simple conditional form of “If,... Then” logic. If my premise is true then the conclusion logically follows.

First the misplaced example from Wikipedia:

Categorical syllogisms always have three terms:

Major premise: All fish have fins.

Minor premise: All goldfish are fish.

Conclusion: All goldfish have fins.

Here, the three terms are: "goldfish", "fish", and "fins".

Using four terms invalidates the syllogism:

Major premise: All fish have fins.

Minor premise: All goldfish are fish.

Conclusion: All humans have fins.

 

My argument again: (note, there is no fourth term stupidly interjected as in the above example):

If earth does not morph, it cannot change from spherical to very oblate. It must be one or the other, i.e., it can not be both. It's diameter can not be "different lengths.

 

We agree on the premise that earth does not “morph,” does not change form drastically, the “If.” The "Then” (obviously implied) is (Then) “... it can not be both. It's diameter can not be "different lengths."

 

Your premises refer to observations in a single frame of reference. But the conclusion refers to a measurement comparison between two frames. At no point did you establish any relationship concerning the invariance of length between frames. Relativity says that it is not invariant. You cannot disprove that with measurements from a single frame.

 

My premise is consistent with the argument promoted in this thread, that objects (including earth) have objective intrinsic properties independent of the frame of reference from which they are observed (realism.) So the conclusion verifies that looking at earth from a different frame of reference will not make its diameter Be different, as in the variation of idealism where frame of reference supposedly establishes a reality in which earth’s diameter IS different.

swansont;

Denigrating the logic because you disagree or don't understand it is hardly an argument. If you disagree you need something more than argument from incredulity.

 

If you find fault with my “for a muon” logic (earth has a very shallow atmosphere), it is up to you to explain the fault... hopefully more cogently than above.

Edited August 17, 2011 by owl

[Cap'n Refsmmat]

You can “reword” it all you want and appeal to “protocols of measurement without error”, but since the earth doesn’t drastically change shape, it IS either very oblate or nearly spherical. In all honesty, it can not be both, in the “real world.”

This would not be a problem if you didn't rashly reject the notion of "spacetime", because in four dimensions, you simply change coordinates. No shape change required. No morphing.

[mississippichem]

I have taught university level “Logic and the Scientific Method” and you are way out of your element (field of expertise) here. I don’t intend to embarrass you personally, but you have grossly misapplied the “fallacy of four terms,” which I just reviewed from your link.

 

You say this as if you haven't been out of your field of expertise the entire thread. If you could see relativity from a scientific and mathematical standpoint, you would see how silly you are being. Keep the philosophy in philosophical circles. Call relativity subjective idealism if you want. It doesn't matter. GPS still works, length contraction is still observed, all of these phenomena still represent absolute, quantifiable, objective reality whether or not you class it into an arbitrary philosophical category that never helped anyone understand anything.

 

We deal in testable predictions and mathematics. Yeah I know this is in the philosophy forum, but you are making such a large strawman on relativity that you've crossed into the scientific realm. Don't be surprised when you get called on it from a site full of physicists. Come back when you know how to work with 4-vectors. Up till now, this has been eight pages of absolute semantic nonsense. This isn't even philosophy.

Edited August 18, 2011 by mississippichem

[tar]

Oblate spheroid folks,

 

If from a stationary point, along the path of the high speed flyby guy, the Earth is a circle, and from the next point, the Earth is a circle, and from the next point the Earth is a circle, at what point is it not a circle?

 

I would think that the Earth could not be seen at all, unless there was light reflecting off of it. And the "shape" of the Earth would always be a result of the amount of the "sky" of the observer that was "filled" by the Earth. Arclength wise, this would be always be the diameter of the Earth whether horizontally considered, or vertically, or diagonally or any diameter direction you wish to consider. There is not a stationary vantage point from where the Earth would not be this circle shape. Why would it matter how fast one changed their observation point? The Earth would always be a circle. At no one point would it ever have a reason to fill a different shape. Would it?

 

Regards, TAR2

[Iggy]

Iggy:

 

 

We look at each situation in all its particulars and apply the scientific method. Your hand in front of your face was an obvious illustration. How do you "know" it is not just a palm when you can't see the back?

Because, ever since we were born we have seen it from all angles and *know* it as a whole hand with all its "intrinsic properties" even when we only see one side or the other. Apply that on all scales to all "known objects." Of course, the more familiar we are with a given object the better, because we have memory and previous records as well as immediate observation as part of empirical science.

A good answer. You know it because you see it every day. In order to deal with the world your mind is programmed with an intuition about what to expect of the world.

 

Your mind expects objects to maintain their dimensions no matter how you rotate the object. There is no preferred direction in space. This is correct and intuitive to you because, as a human, you have to deal with it on a day to day basis to survive in the world.

 

But, you are now dealing with a subject which you, personally, have never dealt with in your life. You have no intuition upon which to draw -- nor should you expect to have an intuition of length contraction, time dilation, and the relativity of simultaneity.

 

Duration can be the time between the "ticks" of a clock (or "clicks" of a stopwatch) or any elapsed time of any physical process under consideration. The physical objects have intrinsic properties, as belabored above, and duration is the concept explained yet again above.

As objects move we can only assign velocity relative to other objects, because that is the meaning of velocity. A car's velocity designated as 60 mph is relative to the road, but a mile-marker on the road is spinning at over 1000 mph relative to the center of earth, and the whole earth is going whatever velocity in orbit around (relative to) the sun, which has whatever velocity relative to the center of the galaxy... etc., etc... to belabor the obvious, yet again.

You again didn't answer why you should expect duration to be intrinsic and not relative to frame of reference, but I haven't expected you to answer. The truth, Owl, is that you don't know why you expect that. You don't know why you claim it as a fact. You have no information upon which you have drawn that conclusion and no reason to expect having any intuition of it. It's quite clear you are just guessing and you are guessing wrong.

 

The duration between two events (between a plane taking off and landing, for example) is not constant. It is different in every different reference frame just as much as velocity is different in every different reference frame. Hafelle and Keating proved it and GPS systems are programmed to "know it" or they couldn't do their job.

 

If you regularly judged duration in terms of nanoseconds or if you accelerated a significant fraction of the speed of light every day then you would have an intuition of it too. But you don't, so if you want to keep talking about the fact of this matter then stop expecting things to be true for no reason at all. Stop expecting your intuition to tell you the truth. It's not going to help you.

[swansont]

 

You can “reword” it all you want and appeal to “protocols of measurement without error”, but since the earth doesn’t drastically change shape, it IS either very oblate or nearly spherical. In all honesty, it can not be both, in the “real world.”

 

Repetition doesn't make this true.

 

 

I have taught university level “Logic and the Scientific Method” and you are way out of your element (field of expertise) here. I don’t intend to embarrass you personally, but you have grossly misapplied the “fallacy of four terms,” which I just reviewed from your link.

 

First I am not using a “categorical syllogism” as exemplified in your link. Rather I am using a simple conditional form of “If,... Then” logic. If my premise is true then the conclusion logically follows.

 

OK, I've reworded it as a conditional

 

If all fish have fins,

and all goldfish are fish,

then all humans have fins

 

Both premises are true. But I don't see how the conclusion logically follows, professor.

 

 

I'm not the one who should be embarrassed here.

 

 

If you find fault with my “for a muon” logic (earth has a very shallow atmosphere), it is up to you to explain the fault... hopefully more cogently than above.

Your "logic" was to harrumph at the notion. The fault is (or at least should be, to a professor of logic) self-explanatory.

[Iggy]

Oblate spheroid folks,

 

If from a stationary point, along the path of the high speed flyby guy, the Earth is a circle, and from the next point, the Earth is a circle, and from the next point the Earth is a circle, at what point is it not a circle?

If earth is spherical at one point in a frame of reference then it is spherical at all points in that frame of reference. At no point is it not.

 

I would think that the Earth could not be seen at all, unless there was light reflecting off of it.

The method of observation shouldn't matter.

 

And the "shape" of the Earth would always be a result of the amount of the "sky" of the observer that was "filled" by the Earth. Arclength wise, this would be always be the diameter of the Earth whether horizontally considered, or vertically, or diagonally or any diameter direction you wish to consider.

The method of measuring distance shouldn't matter. Whatever works.

 

There is not a stationary vantage point from where the Earth would not be this circle shape.

Correct.

 

Why would it matter how fast one changed their observation point?

If there is a speed, less than infinity (call it "c"), that is the same no matter how fast one changes their point of observation then it should matter very much.

[owl]

Cap ‘n R:

This would not be a problem if you didn't rashly reject the notion of "spacetime", because in four dimensions, you simply change coordinates. No shape change required.

No morphing.

 

I wouldn’t call my rejection of spacetime “rash.” I’ve studied criticisms of it for a few years now. (See references in the ontology of spacetime thread.)

And again, my argument is that changing coordinates (frames of reference) does not effect the intrinsic properties of objects observed. So when you say, “for a high speed traveler, earth is an oblate spheroid,” that does not mean that earth *IS* such.

Here is a diagram of the sentence;

Independent clause (primary sense of the sentence); ..."earth is an oblate spheroid."

Dependent clause (condition under which the primary sense is true):

"for a high speed traveler."

So the above condition makes the earth an oblate spheroid.

False.

There is such a thing as the real earth, which does not depend on how that traveler sees it. If you disagree, you are a subjective idealist as presented in contrast to objective realism in this thread. If that is the case, I have made my argument.

 

Swansont:

Your "logic" was to harrumph at the notion. The fault is (or at least should be, to a professor of logic) self-explanatory.

 

My logic compared what we know about incoming natural muons to lab muons, i.e., longer lifespan, and then explained that traveling further through the atmosphere than expected, because of that does not mean that the atmosphere is shallower (length contracted) because of all of the above.

“For a muon” grants a point of view to a muon which contradicts the known depth of earth’s atmosphere. If that happens to be ridiculous, (which it is) it is not that my ridicule makes it so.

 

You say the following is not true... “Repetition doesn't make this true.”:

(me)

“...since the earth doesn’t drastically change shape, it IS either very oblate or nearly spherical. In all honesty, it can not be both, in the “real world.”

 

If you agree that earth does not drastically change shape, then it stays the same shape. It does not depend on how you look at it.

 

If it stays the same shape, what shape is that? (Multiple choice):

Nobody knows.

Nearly spherical, as per the mountain of empirical evidence from earth science, from at rest frame.

Severely oblate, granting equal validity to a frame of reference flying by it at near light speed.

 

Science (with the exception of length contraction advocates)

says it is nearly spherical, not in fact a severely oblate spheroid.

 

You can say “all of the above” but you will be wrong.

 

If all fish have fins,

and all goldfish are fish,

then all humans have fins

 

Both premises are true. But I don't see how the conclusion logically follows, professor.

 

You can't dress up my conditional logic as a categorical syllogism by introducing a fourth term which is not part of the argument, and pretend it is faulty logic on my part.

The Wiki example is intended to show how stupid such fourth term fallacy is in a syllogism ... which it is.

[Cap'n Refsmmat]

And again, my argument is that changing coordinates (frames of reference) does not effect the intrinsic properties of objects observed.

This is, in fact, quite true. You just err when you assume three-dimensional length is an intrinsic property, rather than four-dimensional length.

 

In special relativity, reality comes in four-dimensions. Properties such as the spacetime interval, which is four-dimensional, are invariant between any reference frame, and hence "intrinsic" enough for you. Three-dimensional length or shape is not.

 

Is there a name for the philosophy "reality is real, but we all see different parts of it"?

[swansont]

You can't dress up my conditional logic as a categorical syllogism by introducing a fourth term which is not part of the argument, and pretend it is faulty logic on my part.

The Wiki example is intended to show how stupid such fourth term fallacy is in a syllogism ... which it is.

But you are introducing a fourth term by changing reference frames, but having no premise that tells you anything about changing reference frames. Implicit in your argument is the assumption that length is invariant, but that is not true. Thus, your argument is invalid.

[owl]

This is, in fact, quite true. You just err when you assume three-dimensional length is an intrinsic property, rather than four-dimensional length.

 

In special relativity, reality comes in four-dimensions. Properties such as the spacetime interval, which is four-dimensional, are invariant between any reference frame, and hence "intrinsic" enough for you. Three-dimensional length or shape is not.

 

Is there a name for the philosophy "reality is real, but we all see different parts of it"?

You continue to assert “spacetime” as a given without having addressed any of the criticisms of it presented in the ontology of spacetime thread. If you refuse to engage in discussion of what spacetime is, then we can not have a conversation about it as if non-Euclidean geometry and Minkowski’s spacetime were not an issue, as you seem to assume.

 

I have posted a lot on the assumptions inherent in the transition beyond Euclidean 3-D space and time as merely the movement factor. (Obviously it takes time for things to move around in space even with space as simply volume described by three axes.)

 

An interval is elapsed time for any physical movement through 3-D space. How do you see “the spacetime interval” as four dimensions if different from that, i.e., if not a fourth spatial dimension, which I have often challenged?

In other words, what does “four-dimensional length” actually, ontologically* mean? (*Referring to the objective world.)

How do you explain this four dimensional length?

 

Please present a cogent argument against the following:

Length is one dimensional, a straight line from one point to another. A plane is area, with two dimensions. Space (volume) is three dimensional. Time introduces event duration of movement from one point to another through space.

 

(Please, no lectures on intrinsic vs extrinsic curvature relative to different mental models or conceptual “manifolds.” Have you even looked at the Kelley Ross paper on all of that?... The Ontology and Cosmology of Non-Euclidean Geometry.)

 

To your last question:

The closest form of that philosophy that I know of is called “objective idealism,” which I have called an oxymoron because realism as objectivity and pure subjective idealism are mutually exclusive. But there is a 'gray area’ explained by the following entry from Wikipedia on Objective Idealism:

Objective idealism is an idealistic metaphysics that postulates that there is in an important sense only one perceiver, and that this perceiver is one with that which is perceived. One important advocate of such a metaphysics, Josiah Royce, wrote that he was indifferent "whether anybody calls all this Theism or Pantheism". Plato is regarded as one of the earliest representatives of objective idealism.[1] It is distinct from the subjective idealism of George Berkeley, and it abandons the thing-in-itself of Kant's dualism.

[edit] Difference to other Idealisms

 

Idealism, in terms of metaphysics, is the philosophical view that the mind or spirit constitutes the fundamental reality. It has taken several distinct but related forms. Among them are Objective and Subjective idealism. Objective idealism accepts common sense Realism (the view that material objects exist) but rejects Naturalism (according to which the mind and spiritual values have emerged from material things), whereas subjective idealism denies that material objects exist independently of human perception and thus stands opposed to both realism and naturalism.

 

“One perciever” is clearly theistic, and I dismiss it. But my first emphasis in bold addresses your question. The second bold emphasis requires the explanation I have repeatedly provided: That *the properties of material objects* (not denying the objects per se) exist independently of frames of reference, even abstract ones, not insisting on human perception.

 

Finally, the most common metaphor for your "reality is real, but we all see different parts of it"... is of course the old saw about the three blind men and the elephant.

From one 'frame of reference' it is like a tree trunk. From another, a fire hose. For the third, a rope. (Leg, trunk and tail. I guess none of them felt the belly or climbed on top.)

[Cap'n Refsmmat]

An interval is elapsed time for any physical movement through 3-D space. How do you see “the spacetime interval” as four dimensions if different from that, i.e., if not a fourth spatial dimension, which I have often challenged?

Any physical movement relative to what?

 

After all, if an object is moving at a constant velocity, we can switch to its perspective. In its perspective, it's stationary, and other objects are moving past it. (You've already considered that velocity is relative.) This would imply that from some perspectives, an interval of time elapsed, and from other perspectives, time did not elapse at all. How does that work?

 

Please present a cogent argument against the following:

Length is one dimensional, a straight line from one point to another. A plane is area, with two dimensions. Space (volume) is three dimensional. Time introduces event duration of movement from one point to another through space.

Why is the burden of proof on me?

 

The following proposition is fundamentally different from yours:

 

Length is one dimensional, a straight line from one point to another. A plane is area, with two dimensions. Space (volume) is three dimensional. Spacetime is four dimensional, and time is a dimension unrelated to movement from point to point.

 

This is the view of relativity, and it must be true for numerous experimental results to make sense. If you wish to suggest otherwise, you need to formulate an alternative that can account for those experimental results.

[owl]

This thread is in the philosophy section for good reason.

The gist of this thread’s argument, from my last post:

If you agree that earth (etc.) does not drastically change shape, then it stays the same shape. The same principle holds for lengths and distances between objects (in the "real world", assuming perception/frame of reference does not create reality.) Reality does not depend on how you look at it.

 

If you agree, then you must accept the position of objective realism that earth (and objects, and their spatial relationships) have intrinsic properties not dependent on point of view (frame of reference.)

Of course, the task of science then is to find out what those properties are by minimizing error in the process of investigation.

 

(Again, I advocate the at-rest frame with whatever is investigated as introducing the fewest unknowns and error.)

 

If you disagree, then you accept some version of idealism, which says that various shapes (diameters, etc) of earth and other objects, and distances between them are equally valid, based on the rule that "there are no preferred frames of reference.”

I believe that this dictum constitutes a dogma in disservice to open and unbiased scientific investigation.

 

It is pretty simple really. Relativity’s length contraction is based on a form of idealism which denies an objective universe with properties independent of measurement and observation from different frames of reference. The rest is quibbling over details.

 

Yet I will address some of the recent arguments against the above (soon.)

 

Cap 'n R,

Some unanswered questions:

Do you agree that,

"There is such a thing as the real earth, which does not depend on how that traveler sees it?"

An interval is elapsed time for any physical movement (*note below) through 3-D space. How do you see “the spacetime interval” as four dimensions if different from that, i.e., if not a fourth spatial dimension, which I have often challenged?

In other words, what does “four-dimensional length” actually, ontologically* mean? (*Referring to the objective world.)

How do you explain this four dimensional length?

 

Cap 'n R:

Any physical movement relative to what?

* from any point A to point B.

 

After all, if an object is moving at a constant velocity, we can switch to its perspective. In its perspective, it's stationary, and other objects are moving past it. (You've already considered that velocity is relative.) This would imply that from some perspectives, an interval of time elapsed, and from other perspectives, time did not elapse at all. How does that work?

 

In "the real world," if an object is moving at constant velocity, a virtual coordinate marker (or actual space buoy) could be ejected and retro-jetted to lose all inertial velocity it had with the object (become stationary relative to the object.) This would serve as a 'reality check' to your "In its perspective, it's stationary..."

 

I see "time" as event duration of (any) physical process (EDPP.) Since everything everywhere is moving, there is no case in which time does not elapse at all (unless considering a virtual instant in the ongoing NOW.) Time is not some entity interwoven with another dubious entity, space, according to all criticism of spacetime.

Please address my recent comments on the ontology of spacetime, and immediately above, questioning 4-D space.

 

Spacetime is four dimensional, and time is a dimension unrelated to movement from point to point.

You constantly assert,"Spacetime is four dimensional", as if the whole debate among scientists and philosophers of the International Society for the Advanced Study of Spacetime is over and it's advocates won. this is not the case. (Again, see my spacetime ontology thread and references.)

 

Then you assert that time is not the duration of such an event as movement of an object from point A to point B, as I contend. Do you "win" without an argument, or will you explain what you think time is?

Isn't a day one revolution (the spinning movement) of earth and a year one orbit, movement around the sun?

(See my "ontology of time" thread if interested in the argument on what time is.)

Edited August 19, 2011 by owl

[Cap'n Refsmmat]

It is pretty simple really. Relativity’s length contraction is based on a form of idealism which denies an objective universe with properties independent of measurement and observation from different frames of reference. The rest is quibbling over details.

There are properties independent of measurement and observation from different frames of reference. They are called "invariants," and they are very useful in relativity. Spacetime intervals are one example, but there are many others.

 

In short: there are properties of reality which do not change no matter who you are or where you are. There are other properties that do. Unfortunately, these properties do not match your expectations.

 

I believe that this dictum constitutes a dogma in disservice to open and unbiased scientific investigation.

Have you conducted an unbiased scientific investigation into the reasons for the existence of the dictum?

[tar]

Spacetime is four dimensional, and time is a dimension unrelated to movement from point to point.

 

Cap'n Refsmmat,

 

How can time be unrelated to movement from point to point, if movement from point to point, takes it (time)?

 

It takes a collection of matter (entity C) "time" to make the trip between collection of matter A, and collection of matter B.

 

In addition, since A and B are separated by this distance that it take "time" for C to transit, it take "time" for even light to make the trip between A and B.

 

Thus there is the "time" it takes matter to make the trip, AND there is the "time" it takes light to make the trip.

 

I think the distance between A and B can be defined as either the time it takes matter to make the trip, or the time it takes light to make the trip, and that these "distances" will equate.

 

 

There is a problem with considering "real", the idea that point A and point B are "no distance" from each other. If relativity requires that point A and point B be at the same point, in any dimension, that dimension must be hypothetical or "without" dimension.

 

Regards, TAR2

[owl]

Cap 'n R:

Have you conducted an unbiased scientific investigation into the reasons for the existence of the dictum?

 

Like any other honest scientist (non-pro though I am) I have studied the real-world referents and phenomena which relativity addresses, and, like many others frequently cited in my ontology threads, I find good reason to disbelieve that a flattened version of earth or a shortened version of the AU or the meter rod (which, by consensus have no direct experimental evidence to support them) are equally as correct as the well established standard science textbook versions versions of earth, the meter and the AU.

 

I will patiently await your answers to my recent questions.

Edited August 19, 2011 by owl

[Iggy]

I have studied the real-world referents and phenomena which relativity addresses, and... I find good reason to disbelieve that a flattened version of earth... are equally as correct...

Perhaps in the recesses of your mind exits a fantastic vault of reasoning supporting your belief. But, I can't help notice, you've failed entirely in expressing it.

 

Could you, again, try giving one reason why (never mind a "good reason") distance should be constant and not relative?

 

Once you do that, and, again, you have completely failed thus far -- All of your work is still ahead of you! You must then apply that exact same reasoning to the concept of velocity (or momentum or any other property you've picked out of the frame-dependent hat) and come up with an entirely different answer.

 

I'm holding my breath in anticipation.

[Cap'n Refsmmat]

"There is such a thing as the real earth, which does not depend on how that traveler sees it?"

Yes.

 

In other words, what does “four-dimensional length” actually, ontologically* mean? (*Referring to the objective world.)

How do you explain this four dimensional length?

This four-dimensional length reflects the spatial and temporal distance between any two events; in other words, it's a distance through time and space.

 

It "actually" means [math]s^2 = \Delta x^2 - c^2 \Delta t^2[/math]. I'm not in a position to explain ontologically because an ontology is not empirically observable, and hence outside my purview.

 

In "the real world," if an object is moving at constant velocity, a virtual coordinate marker (or actual space buoy) could be ejected and retro-jetted to lose all inertial velocity it had with the object (become stationary relative to the object.) This would serve as a 'reality check' to your "In its perspective, it's stationary..."

 

I see "time" as event duration of (any) physical process (EDPP.) Since everything everywhere is moving, there is no case in which time does not elapse at all (unless considering a virtual instant in the ongoing NOW.) Time is not some entity interwoven with another dubious entity, space, according to all criticism of spacetime.

Whoa. Earlier (post #133) you wanted to choose a reference frame where an object is stationary; now you say that no such frame exists.

 

You say "if an object is moving at constant velocity" -- relative to what? Relative to object A it may be moving at 20 m/s and relative to object B it may be moving at 10 m/s. Your virtual marker be retro-jetted to be stationary according to whom?

 

As you said, "velocity requires a specific reference, i.e., relative to what?", so I'm going to choose a specific reference that is the object which is moving. There. Relative to itself, it's not moving. It's stationary. By your argument, that's "the preferred frame for objective accuracy of measurement". So it's not moving. So an interval for the elapsed time for its motion is null, because it has no motion.

 

How does that work? Your scenario does not make sense.

 

You constantly assert,"Spacetime is four dimensional", as if the whole debate among scientists and philosophers of the International Society for the Advanced Study of Spacetime is over and it's advocates won. this is not the case. (Again, see my spacetime ontology thread and references.)

I thought we were talking about how relativity works with frames of reference. Would you prefer to talk about some other theory that doesn't involve a four-dimensional spacetime?

 

Then you assert that time is not the duration of such an event as movement of an object from point A to point B, as I contend. Do you "win" without an argument, or will you explain what you think time is?

A dimension.

 

Isn't a day one revolution (the spinning movement) of earth and a year one orbit, movement around the sun?

No. A day is 86,400 seconds and a year 365.25 days.

[swansont]

This thread is in the philosophy section for good reason.

The gist of this thread’s argument, from my last post:

If you agree that earth (etc.) does not drastically change shape, then it stays the same shape. The same principle holds for lengths and distances between objects (in the "real world", assuming perception/frame of reference does not create reality.) Reality does not depend on how you look at it.

 

If you agree, then you must accept the position of objective realism that earth (and objects, and their spatial relationships) have intrinsic properties not dependent on point of view (frame of reference.)

Of course, the task of science then is to find out what those properties are by minimizing error in the process of investigation.

 

No, science does not start with an ideology or philosophy and then look for data to support it. That is not the task of science. Science may make assumptions, but it tests those assumptions. The assumption that length is an intrinsic property has been tested and it was falsified.

[owl]

me:

"There is such a thing as the real earth, which does not depend on how that traveler sees it?"

Cap 'n R;

"Yes."

Then it is as it is regardless of frame of reference, as per objective realism.

Cap 'n:

This four-dimensional length reflects the spatial and temporal distance between any two events; in other words, it's a distance through time and space.

 

It "actually" means s^2 = Delta x^2 - c^2 Delta t^2. I'm not in a position to explain ontologically because an ontology is not empirically observable, and hence outside my purview.

 

I understand 3-D space as I've laid out the dimensions many times.

I understand time as the duration it takes things to move, however far, however long it takes. So what does "through time" mean but the duration of travel from A to B?

 

You:

Whoa. Earlier (post #133) you wanted to choose a reference frame where an object is stationary; now you say that no such frame exists.

 

You say "if an object is moving at constant velocity" -- relative to what? Relative to object A it may be moving at 20 m/s and relative to object B it may be moving at 10 m/s. Your virtual marker be retro-jetted to be stationary according to whom?

 

... Referring to my:

 

That everything is moving everywhere, so velocity requires a specific reference, i.e., relative to what? I argue that at rest (no relative velocity between observer and observed) is the preferred frame for objective accuracy of measurement.

 

You missed the central point, in bold above. That does not contradict the first sentence. My space buoy was ejected from your moving object and retro-jetted to lose all the velocity it had while moving with the object, therefore becoming a stationary reference point relative to the object, which is still moving at the same velocity. This was suggested as a reality check for your assertion that, once you are on that object, it has no velocity, which is true relative to you, along for the ride, but not now relative to the buoy.

 

You go on to say:

I'm going to choose a specific reference that is the object which is moving. There. Relative to itself, it's not moving. It's stationary. By your argument, that's "the preferred frame for objective accuracy of measurement". So it's not moving.So an interval for the elapsed time for its motion is null, because it has no motion.

 

Fine. Riding the object, at rest with it will be the best frame from which to measure and describe it. My point was that it is still moving away from (relative to) the ejected buoy, and as time passes (seconds tick away) it moves further from the buoy without making some entity out of time. Of course it is not moving relative to you, its passenger.

You:

I thought we were talking about how relativity works with frames of reference. Would you prefer to talk about some other theory that doesn't involve a four-dimensional spacetime?

 

I objected to your using a concept that is still in hot debate as if it were a given as part of your explanation.

To my "what is time":

"A dimension."

How is the elapsed time between two clicks of a stopwatch (just to simplify) a dimension? It is the duration of any designated physical movement, yes? If you insist on calling that factor a dimension, fine.

 

No. A day is 86,400 seconds and a year 365.25 days.

"No?" Just because you can specify how many seconds in a day and days in a year, a day is no longer one full revolution nor a year one full orbit? So real world referents are no longer relevant to passage of time?

This should not surprise me considering that spacetime, (for example) works as a mathematical coordinate system without any ontological concern for what it actually is, if anything, in the "real world." (See ontology of spacetime thread.)

[Cap'n Refsmmat]

I objected to your using a concept that is still in hot debate as if it were a given as part of your explanation.

To my "what is time":

"A dimension."

How is the elapsed time between two clicks of a stopwatch (just to simplify) a dimension? It is the duration of any designated physical movement, yes? If you insist on calling that factor a dimension, fine.

No.

 

Time is independent of ticks of stopwatches.

 

I am not in a position to fully explain the nature of spacetime and its meaning of relativity to you. I suggest a good textbook. You need to understand special relativity fully before we can have this discussion.

[owl]

No, science does not start with an ideology or philosophy and then look for data to support it. That is not the task of science. Science may make assumptions, but it tests those assumptions. The assumption that length is an intrinsic property has been tested and it was falsified.

Philosophy of science examines its basic assumptions, the focus of this thread. Is the world as-is, in- and- of- itself and all its parts, independent of observation/measurement (objective realism);...

Or is there no physical "reality" other than how we see the world (idealism; frame of reference determines reality.)

 

Just so you understand the philosophical issue at hand here.

 

As far as I know, all scientists except advocates of length contraction describe earth very precisely as very nearly spherical, an AU remains about 93 million miles even when (if) viewed as an eighth or so of that from the overworked extreme frame we've been discussing; and a meter remains a ten millionth of the surface quadrant of earth, equator to pole, even when a near 'C' frame sees it as about 12 cm.

 

No.

 

Time is independent of ticks of stopwatches.

 

I am not in a position to fully explain the nature of spacetime and its meaning of relativity to you. I suggest a good textbook. You need to understand special relativity fully before we can have this discussion.

Here is a little review of the ontological question, "What is time?" from my other threads:

 

Marat, post 7, Ontology of Time:

There is no 'time' lying underneath 'time measurement' whose ontology-in-itself has to be determined -- since if there was, what would measure it?

I agree. As events happen, we can measure their duration and assign conventional "time units" by which clocks are calibrated.

 

Do you disagree, Cap ‘n? If so, how so?

 

On my understanding of SR,

Ross:

Just because the math works doesn't mean that we understand what is happening in nature. Every physical theory has a mathematical component and a conceptual component, but these two are often confused. Many speak as though the mathematical component confers understanding..."

(My bold)

I understand very well what the conceptual components of SR are.

 

Deiks on spacetime (that it is debatable, not a given, as you use it):

 

Deiks summarizes this debate as follows:

(If Brown and Pooley are right)…”There is no causal mechanism involved: Spacetime does not send signals to which particles respond. More generally, exactly how does spacetime inform the laws of nature? Failing a detailed account of what the purported explanation consists in, it can hardly be maintained that the existence of space and time is the only plausible conclusion"...

(my bold again)

 

From ontology of time, starting with my post 50:

“What slows down because of the effects of relativity?” Physical processes do for sure, but that doesn’t make time a malleable entity, some “thing” that “dilates”... the essence of this thread’s challenge.

and:

What is time transformation but change in the rate (speeding up or slowing down) of physical processes?

and:

If time is not a reference to the "event duration" of physical processes (clocks ticking, planets orbiting, galaxies rotating, cosmic lifespan or cycling), what then... what "transforms?"

and:

As some of us here have agreed, any physical process can be called a clock in the broadest sense. So even if there were no intelligent life with clocks as we know them, we can say that it “takes time” for all physical processes to happen... for all movement.

Cap ‘n R (same thread):

“Hence it is meaningless to talk about time as something other than what clocks measure.

 

Do you realize that it is a meaningless tautology to say that “Time is that which clocks measure?” ("Time is that"... that what but duration?)

As an event is happening (any physical process) we can measure its duration by the elapsed time on a clock (adjusting for the effects of velocity, gravity, etc., as needed.) The clock measures the time it takes for actual processes to happen.

 

From Lysa Zyga, quoted in post 51, spacetime ontology thread:

In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary physical existence.

 

Comments?

(I'll be gone for the weekend.)